Generally, the cushion body has a structure in which a soft cushion material such as polyurethane foam is mounted on a structure body finally supporting pressure of a wire or a flat plate-like supporting body extended to a frame body, and a whole of them is covered with a surface cover. Further, the structure body does not inhere in the floor cushion and the mattress of the bed themselves, however, the floor cushion and the mattress of the bed are generally used by being mounted on the structure body such as the floor and the frame body of the bed which can support the pressure of the human body.
In the general cushion body, vibration and shock applied to the cushion material has been lightened mainly by reaction force, restoring force and deflection when the soft cushion material such as the polyurethane foam interposed between the structure body and the surface cover deflects in a compression direction.
Further, as a technique relating to the weight reduction of the seat cushion for vehicle, patent document 1 describes a technique that a seat frame exhibit a frame structure, a cross section of the seat frame exhibits a mountain shape, an inclined surface facing to a seated person is provided by forming one side of the mountain shape in an inner peripheral side of the frame shape of the seat frame, the seat frame is covered with a net having an elasticity, a peripheral edge portion of the net is provided in a tension manner so as to form a seating surface having a concave curve surface shape by being taken around from the mountain shape of the seat frame and fixed to the other side of the mountain shape, and an angle is provided between the net and the inclined surface of the seat frame.
As the other technique relating to the weight reduction, patent document 2 describes a technique relating to a seat for vehicles having a seating portion provided with a base plate which is arranged on a seat frame in an attachable and detachable manner, a block which is arranged on the base plate, a spring plate which is arranged on the block, and a surface cover 7 which covers the spring plate. The block is arranged so as to form a predetermined space between the base plate and the spring plate. The spring plate is formed by a foam which has an elasticity and is made of any of a PP (polypropylene) bead foam, a PE (polyethylene) bead foam, a PP foam, a PE foam, an AS resin (acrylonitrile-styrene copolymer resin) foam, an EVA (ethylene-vinyl acetate copolymer resin), and an polyurethane foam material. The spring plate is deflected into the predetermined space when force in a direction toward the base plate is applied.
Next, the bed mattress generally uses the polyurethane foam as the cushion material in the case that the cushion body is assembled for the bed mattress. As the technique relating to the weight reduction of the bed mattress, patent document 3 describes a technique that the supporting body is constructed by the polyurethane foam, and is provided on its surface with a plurality of concave grooves reaching both end portions in a short side direction, the concave groove has a depth 30 to 70 mm and a width 15 to 80 mm, a core material is constructed by a rectangular polyurethane foam having a thickness 10 to 40 mm and a hardness 100 to 300 N, is folded its short sides into two in a long side direction, and is fitted and supported in both end portions of its long sides to one concave groove of the supporting body, and the frame body is provided so as to surround the periphery of the supporting body.